Dr. Michael Fulks discusses the overlooked link between obesity and cancer, the potential impact on mortality risk, and potential solutions for reducing it.
The authors at CRL have published papers in OTR and The Journal of Insurance Medicine on the obesity epidemic documenting its all-cause mortality risk as well as papers on cardiovascular disease and diabetes mellitus noting their links to obesity. These can be found here. But don’t forget a third major (but less intuitive) source of excess mortality associated with obesity – CANCER.
Almost 10% of cancers in women and 5% in men may be due to obesity (BMI 30+) according to the NCI fact sheet and its referenced papers. With over 40% of the population now obese (increasing every year), this is a terrible burden not just for each person and family afflicted but for our society. Breast, ovarian, pancreatic, colon, and other GI cancers are increased by 30% or more and endometrial cancer by much more than that with the risk increasing with the degree of obesity. Suggested causal mechanisms are estrogen production by fat tissue, increased insulin and insulin-like growth factor-1 production, inflammation, and other hormone production by fat cells, but our understanding of the link(s) is currently limited. Not only are many cancers more common but the outcome may be poorer according to this recent review article.
The increased cancer risk appears largely limited to BMIs of 30+ and increases with higher BMI – begging the question if the increased risk can be removed by weight loss below this BMI. The answer is – we don’t know, although limited data referenced in the fact sheet suggest sustained weight loss or bariatric surgery may reduce future risk. We have little data because of the infrequent success in achieving sustained weight loss by any method other than surgery where reports are typically based on small, self-selected treatment cohorts making interpretation challenging. Hopefully, GLP-1 agonists, such as semaglutide, which have now been used by 1 in 8 Americans will improve sustained weight loss but proof of cancer reduction for these expensive drugs will require continued use to maintain weight loss and long-term follow-up.
Americans obsess about potential external causes of cancer even when the risk increase is small, unproven or disproven while ignoring the increasingly obvious cause, their expanding waistlines.
About the Author
Michael Fulks, MD, Consulting Medical Director, is board-certified in internal and insurance medicine. After leaving practice, he served as a medical director, creating or editing several underwriting manuals and preferred programs. More recently, Mike has consulted for CRL participating in its mortality research on laboratory test results, BP and build, and in the development of risk-scoring tools for laboratory and non-laboratory data.